- Reference
- Taxon 64:1204 (2015)
- Conservation Code
- Not threatened
- Naturalised Status
- Alien to Western Australia
- Name Status
- Current
Distribution
- IBRA Regions
- Avon Wheatbelt, Carnarvon, Coolgardie, Esperance Plains, Gascoyne, Geraldton Sandplains, Jarrah Forest, Little Sandy Desert, Mallee, Murchison, Nullarbor, Swan Coastal Plain, Warren, Yalgoo.
- IBRA Subregions
- Augustus, Cape Range, Eastern Goldfield, Eastern Murchison, Edel, Fitzgerald, Geraldton Hills, Katanning, Lesueur Sandplain, Merredin, Northern Jarrah Forest, Nullarbor Plain, Perth, Recherche, Rudall, Southern Jarrah Forest, Tallering, Warren, Western Mallee, Western Murchison, Wooramel.
- IMCRA Regions
- Leeuwin-Naturaliste, Shark Bay.
- Local Government Areas (LGAs)
- Augusta Margaret River, Busselton, Carnarvon, Chapman Valley, Chittering, Claremont, Coolgardie, Corrigin, Cottesloe, Cue, Cunderdin, Dalwallinu, Dandaragan, Dowerin, Dundas, East Pilbara, Esperance, Exmouth, Gnowangerup, Greater Geraldton, Kalgoorlie-Boulder, Koorda, Kulin, Laverton, Leonora, Manjimup, Menzies, Merredin, Mingenew, Moora, Murray, Northampton, Perenjori, Perth, Quairading, Ravensthorpe, Rockingham, Sandstone, Shark Bay, Swan, Upper Gascoyne, Victoria Plains, Wanneroo, Westonia, Wongan-Ballidu, Yalgoo, York.
Management Notes (for the Swan NRM Region)
Alternative Names. Emex australis.
General Biology. Growth form. Herb. Life form. Annual. Reproduction. Seed germination.. Dispersal. Seed dispersal by wind, water, humans and animals.. Seedbank persistence. 4+ years.
Notes. Doublegee is a low-growing annual herb that grows up to 40 cm high, with stems up to 80 cm long, mostly lying on or close to the ground. Its leaves are triangle to ovate, 3 to 12 cm long, 2 to 10 cm wide, glabrous, undulate margins; lower leaves on long stalks, others on stalks about the same length or shorter than the leaf blades, each leaf stalk surrounded by a membranous sheath at the base. The male flowers are in small stalked clusters, the female flowers are almost sessile in the leaf axils. When the fruits ripen, the colour will change from green to brown, hard and woody, 7 to 11 mm long, triangular in longitudinal cross-section. Its seed is brown, roughly triangular, 3 to 4 mm long, smooth, glossy, 1 in each fruit. The root is deep fleshy taproot..
Additional information. Origin. Native to southern Africa.. History of use/introduction. The introduction and spread of Doublegee in Australia appears to have started in 1830 in Western Australia. It was probably brought in from Africa for use as a vegetable or as a contaminant of stock feed, or attached to clothing, shoes, or equipment.. Similar exotic species. Emex spinosa.
Suggested method of management and control. Small infestations and isolated plants of Doublegee can be grubbed out. If the plants are seeding, then they should be completely destroyed by burning them. A control program must aim at killing all plants shortly after emergence and needs to be continued for several years. 'Prickle rollers' have been developed to gather and remove surface Doublegee fruit from drying greens in vineyards. Cultivation kills seedlings, and can be effective when combined with chemical control. Read the manufacturers' labels and material safety data sheets before using herbicides. For further information consult the Australian Pesticides and Veterinary Medicines Authority to determine the status of permits for your situation or state.
Management Calendar
| Calendar Type | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Comments |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Germination | O | O | Y | Y | Y | Y | Y | Y | O | O | O | O | any time after rain |
| Optimum Treatment | Y | Y | Y | Y | Y | Y | |||||||
| Flowering | Y | Y | Y | Y | Y | ||||||||
| Manual Removal | Y | Y | Y | Y | Y | Y | Y | ||||||
| Fruiting | O | O | O | O | O | O | O | O | Y | Y | Y | O | Spiny seed |
| Herbicide Treatment | Y | Y | Y | Y | Before seed set | ||||||||
| Active Growth | Y | Y | Y | Y | Y | Y |
Legend: Y = Yes, regularly, O = Occasionally, U = Uncertain, referred by others but not confirmed.
References
- Brown, K. & Brooks, K. (2002) Bushland Weeds: A Practical Guide to their Management. Environmental Weeds Action Network, Greenwood.
- Cheam, A.H. (1987) Emergence and survival of buried doublegee (Emex australis Steinh.) seeds. Australian Journal of Experimental Agriculture, 27 (1): 101 - 106.
- CSIRO (2006) Biological control of Emex: the weed and potential agents. CSIRO Australia URL: http://www.csiro.au/resources/ps2hf.html - Accessed April 2010.
- Department of Jobs, Precincts and Regions (2017) Spiny emex. Agriculture Victoria URL: http://agriculture.vic.gov.au/agriculture/pests-diseases-and-weeds/weeds/a-z-of-weeds/spiny-emex.
- Department of Primary Industries Queensland (2007) Spiny Emex. State of Queensland URL: http://www.dpi.qld.gov.au/documents/Biosecurity_EnvironmentalPests/IPA-Spiny-Emex-PP39.pdf.
- Gilbey, D.J. (1977) Selective chemical control of doublegee (Emex australis) in legume pasture. Australian Journal of Experimental Agriculture and Animal Husbandry, 17 (84): 80-85.
- Gilbey, D.J., Weiss, P.W. & Shepherd, R.C.H. (1998) Emex australis Steinh. In The Biology of Australian Weeds Vol. 2. (eds. F.D. Panetta, R.H. Groves, and R.C.H. Shepherd). R.G. & F.J. Richardson, Melbourne.
- Hussey, B.M.J., Keighery, G.J., Dodd, J., Lloyd, S.G. & Cousens, R.D. (2007) Western Weeds. A guide to the weeds of Western Australia. 2nd Edition. The Plant Protection Society of Western Australia, Victoria Park.
- Moore, C.B. & Moore, J.H. (2002) Herbiguide, the pesticide expert on a disk. Herbiguide, PO Box 44 Albany, Western Australia, 6330.
- Panetta, F.D. & Randall, R.P. (1994) An assessment of the colonising ability of Emex australis. Australian Journal of Ecology, 19: 76-82.
- Pannetta, F.D. & Randall, R.P. (1993) Emex australis and the competitive heirachy of a grazed annual pasture. Journal of Applied Ecology, 30: 373-379.
- Parsons, W.T. & Cuthbertson, E.G. (2001) Noxious weeds of Australia. 2nd Edition. CSIRO Publishing, Collingwood.
- Parsons, W.T. & Cuthbertson, E.G. (2001) Noxious weeds of Australia. 2nd Edition. CSIRO Publishing, Collingwood.
- Peltzer, S. (2019) Doublegee. Department of Primary Industries and Regional Development URL: https://www.agric.wa.gov.au/grains-research-development/doublegee?page=0%2C0 - Accessed May 2019.
- Pest and Disease Information Service (PaDIS) (2018) Doublegee: pest. Department of Primary Industries and Regional Development URL: https://www.agric.wa.gov.au/declared-plants/doublegee-pest - Accessed June 2019.
- Scott, J.K., Bowran, D.G. & Corey, S.A.( eds) (1996) Emex australis: Biology, management and research. Proceedings of a workshop held CSIRO, Floreat, WA on 11 December 1995. Plant Protection Quarterly, 11 (4) URL: http://www.weeds.crc.org.au/documents/emex_australis.pdf - Accessed December 2007.
- Tindale, D. & Thomson, J. (2016) Report the prickly pest doublegee. Department of Primary Industries and Regional Development URL: https://www.agric.wa.gov.au/news/report-prickly-pest-doublegee - Accessed June 2019.
- Weiss, P.W. (1981) Spatial distribution and dynamics of populations of the introduced annual Emex australis in south-eastern Australia. Journal of Applied Ecology, 18 (3): 849-864.
- Weiss, P.W. (2006) Some effects of competition between Emex australis and E. spinosa. Weed Research, 17 (5): 321 - 324.